印染废水超滤工艺中操作方式对过滤速率的影响

Influence of operation conditions on filtration rate in ultrafiltratin system of dyeing and printing wastewater

对某印染厂废水处理站排水进行了回用处理研究。在恒压条件下,采用聚乙烯(PE)中空纤维膜,进行间歇曝气扫流过滤,分析了不同操作方式对超滤速率变化的影响。结果表明曝气在超滤中能够起到防止污染的作用,解除作用于颗粒上的抽吸力后再采用曝气扫流,则能达到更好的扫流效果。周期运行与非周期运行之间的差距较大,按"曝气过滤-暂停-曝气扫流"<"不曝气过滤-暂停-曝气扫流"<"连续曝气扫流"的顺序阻力增大,因此采用周期运行方式在一定程度上可以恢复超滤速率。印染废水过滤中,在抽吸压力小于0.08 MPa的范围内,可以不考虑沉积物的压缩性。

The treatment before reuse of wastewater from a dyeing and printing plant is studied. Under the constant pressure,the wastewater is filtered by polyethylene hollow-membrane which is intermittently cleaned by aeration and tractive current,and the influence of operational conditions on the filtration rate is analyzed. The result shows that aeration plays a positive role in anti-pollution of membrane. Relieving the suction force on the particles first and then adopting aeration tractive current may enhance the tractive current effectiveness. Difference between the results from cyclic operation and noncyclie operation is significant and the effectiveness is followed the sequence as（aeration filtrationpause-aeration tractive current） 〈 （no aeration filtration-pause-aeration tractive current） 〈 （continuous aeration tractive current）. Thus the filtration rate can be resumed by the cyclic operation in certain degrees. In the course of filtrating of dyeing and printing wastewater, if the suction pressure is less than 0.08 MPa, the compressibility of cake can be ignorable.